‘Good’ Cholesterol May Not Be So Great After All

Bad news for good cholesterol: A Danish study published in European Heart Journal finds that people with extremely high high-density lipoprotein (HDL, often called “good” cholesterol) levels face a higher, not lower, risk of death.

Cholesterol as a substance is neither good nor bad, but an important part of our body chemistry. Like most things, in moderation, it's fine; the health risks set in once our levels get out of whack. Scientists and doctors have long understood cholesterol as a sort of angel-on-one-shoulder, devil-on-the-other situation, in which low-density lipoprotein (LDL) is harmful and HDL is helpful. HDL mediates LDL's negative effects, which means that having more HDL is good.

Or at least that's what we thought.

Researchers pulled health information on 116,000 people from the Copenhagen City Heart Study and the Copenhagen General Population Study, then cross-checked it against death reports from the Danish Civil Registration System. They followed study subjects for six years, during which more than 10,500 people died.

What they found surprised them. Extremely high levels of HDL were associated with significantly greater risks of death than normal levels—68 percent higher for women and a staggering 106 percent for men. Men with very high HDL (one step down from "extremely high") were 36 percent more likely to die.

"These results radically change the way we understand 'good' cholesterol. Doctors like myself have been used to congratulating patients who had a very high level of HDL in their blood. But we should no longer do so, as this study shows a dramatically higher mortality rate," co-author Børge Nordestgaard of the University of Copenhagen said in a statement.

Before we get too worried, it's worth noting that these extremely high HDL levels were incredibly rare, affecting only 0.4 percent of male participants and 0.3 percent of women. The researchers say these people were also more likely to share unusual genetic variants. It's possible that these genes and not the cholesterol are responsible for their higher mortality rates.

Some elements of our ideas about cholesterol still held true. People with extremely low HDL levels also faced an increased mortality risk.

The safest levels seemed to be right in the middle, at 1.9 mmol/L for men and 2.4 mmol/L for women.

More research is needed, as this study focused exclusively on white Danish people and only looked at correlation, not causation.

Still, Nordestgaard said, "It appears that we need to remove the focus from HDL as an important health indicator in research, at hospitals and at the general practitioner. These are the smallest lipoproteins in the blood, and perhaps we ought to examine some of the larger ones instead."

Scientists have developed a new way to cut off the blood flow to cancerous tumors, causing them to eventually shrivel up and die. As Business Insider reports, the new treatment uses a design inspired by origami to infiltrate crucial blood vessels while leaving the rest of the body unharmed.

A team of molecular chemists from Arizona State University and the Chinese Academy of Sciences describe their method in the journal Nature Biotechnology. First, they constructed robots that are 1000 times smaller than a human hair from strands of DNA. These tiny devices contain enzymes called thrombin that encourage blood clotting, and they're rolled up tightly enough to keep the substance contained.

Next, researchers injected the robots into the bloodstreams of mice and small pigs sick with different types of cancer. The DNA sought the tumor in the body while leaving healthy cells alone. The robot knew when it reached the tumor and responded by unfurling and releasing the thrombin into the blood vessel that fed it. A clot started to form, eventually blocking off the tumor's blood supply and causing the cancerous tissues to die.

The treatment has been tested on dozen of animals with breast, lung, skin, and ovarian cancers. In mice, the average life expectancy doubled, and in three of the skin cancer cases tumors regressed completely.

Researchers are optimistic about the therapy's effectiveness on cancers throughout the body. There's not much variation between the blood vessels that supply tumors, whether they're in an ovary in or a prostate. So if triggering a blood clot causes one type of tumor to waste away, the same method holds promise for other cancers.

But before the scientists think too far ahead, they'll need to test the treatments on human patients. Nanobots have been an appealing cancer-fighting option to researchers for years. If effective, the machines can target cancer at the microscopic level without causing harm to healthy cells. But if something goes wrong, the bots could end up attacking the wrong tissue and leave the patient worse off. Study co-author Hao Yan believes this latest method may be the one that gets it right. He said in a statement, "I think we are much closer to real, practical medical applications of the technology."

About 6 million people in the U.S. and Europe have severe peanut allergies, including more than 2 million children. Now, French biotechnology company DBV Technologies SA has secured an FDA review for its peanut allergy patch, Bloomberg reports.

If approved, the company aims to start selling the Viaskin patch to children afflicted with peanut allergies in the second half of 2018. The FDA's decision comes in spite of the patch's disappointing study results last year, which found the product to be less effective than DBV hoped (though it did receive high marks for safety). The FDA has also granted Viaskin breakthrough-therapy and fast-track designations, which means a faster review process.

DBV's potentially life-saving product is a small disc that is placed on the arm or between the shoulder blades. It works like a vaccine, exposing the wearer's immune system to micro-doses of peanut protein to increase tolerance. It's intended to reduce the chances of having a severe allergic reaction to accidental exposure.

The patch might have competition: Aimmune Therapeutics Inc., which specializes in food allergy treatments, and the drug company Regeneron Pharmaceuticals Inc. are working together to develop a cure for peanut allergies.